note about cold-starts

Author: thomas-tacquet

pages/serverless-containers/faq.mdx

@@ -140,6 +140,8 @@ Ensure that your code avoids heavy computations or long-running initialization a
 
 * **Use sandbox v2**: We recommend you use sandbox v2 (advanced settings) to reduce cold starts.
 
+* **Reduce image size**: Ensure to keep your image small and clean: [read more](/serverless-containers/reference-content/containers-limitations/#image-size)
+
 ### Which Linux syscalls are supported?
 
 - [Sandbox](/serverless-containers/concepts/#sandbox) v1 guarantees full compatibility with Linux syscalls.